Can I run two networks in the same place

Archived from groups: alt.internet.wireless (More info?)

Guys,
A hotel need a plasma display showing content from a pc but
they don't wont us to run cables from a pc which is the best way of course,
So we are thinking of using a OTC Wireless Data 802.11g adapter to send
content playing on pc
which will be Flash files of different animations to the plasma, anybody
ever done this?, and will it play smothly

But also the Hotel already has a Wireless network for the guests laptops
Can we run two together?, We cant change the current AP so any changes
have to be done to our setup

Would it be better to run the plasma and pc in adhoc mode or as a 2nd AP?
This will be playing 24hrs so I need to make sure these two networks are not
going to crash each other,

Any advice would be very good

Thanks
Oliver

Archived from groups: alt.internet.wireless (More info?)

In article <32eivoF3k1mj1U1@individual.net>,
Oliver Gunnell <Oliver.spamGunnell@dsl.pipex.com> wrote:
: A hotel need a plasma display showing content from a pc but
:they don't wont us to run cables from a pc which is the best way of course,
: So we are thinking of using a OTC Wireless Data 802.11g adapter to send
:content playing on pc
:which will be Flash files of different animations to the plasma, anybody
:ever done this?, and will it play smothly

Doable in theory, if not with that exact equipment then with some
other, especially if the display signal itself is digital. With
analog you have to worry about phase changes, colour shifts,
and probably other things I'm forgetting.


:But also the Hotel already has a Wireless network for the guests laptops
:Can we run two together?, We cant change the current AP so any changes
:have to be done to our setup

Yes, you should be able to do that. If the existing network is
11b or 11g then you'd be best off running an 11a connection to
the display, but that's not a strict necessity. Multiple networks
can exist in the same place. Best is if they do not use overlapping
channels. 11g provides for 3 channels, each of which overlaps several
11b channels. If you do end up using a channel that is in use by
something else, the effect will be to reduce the maximum effective
transmission rate you can use, either through interference corrupting
the bits, or through the AP's noticing each other's existance and
using flow control to regulate who talks at any one time.

If the hotel's guest wireless network permits 11b connections
(and it very likely does, as it would not want to insist that guests
use 11g equipment they might not own), then if the frequencies
overlap the ones you are using for the plasma display, the
reduction in maximum transmission rate is about 1/3 -- that is,
if there are nearby 11b devices in the same frequency
bands, then even if the devices aren't talking much, you will only
be able to get about 2/3 of the transmission rate that you would if
the 11b devices weren't there at all. So you really want to avoid
overlap with the hotel network if possible. Then you run into the
problem that the guests are going to be running wireless networks
between themselves, and those are going to interfere.... That is
why 11a is a much better choice for your purposes than 11g:
relatively few guests will be using 11a devices amongst themselves,
and 11a channels do not overlap with each other at all.


:Would it be better to run the plasma and pc in adhoc mode or as a 2nd AP?

Infrastructure mode, not adhoc, I would say.

I would further suggest that you use directional antenna, not omni.
The more directional the better -- not for signal strength reasons,
but to decrease the interference of random other wireless signals around.
A carefully aimed sector antenna might do the trick -- particularily
if you can put in reflectors to block the beam from travelling onward
indefinitely.

:This will be playing 24hrs so I need to make sure these two networks are not
:going to crash each other,

You should start thinking about the security mechanism you are
going to use. If you use WEP then a bored guest who was going to be
around for a few hours or days could find your WEP key and then
would be able to change the sign to read things you'd rather not have
appear...
--
'ignorandus (Latin): "deserving not to be known"'
-- Journal of Self-Referentialism

Archived from groups: alt.internet.wireless (More info?)

> <Oliver wrote:
>
>
> >A hotel need a plasma display showing content from a pc but
> >they don't wont us to run cables from a pc which is the best way of
course,
>
> What type of plasma display? One of those orange colored giant neon
> lamp contraptions like I used to use on a Compaq lunchbox, or a 16:9
> wizbang giant screen color plasma display, or something in between?
>
> >So we are thinking of using a OTC Wireless Data 802.11g adapter to
send
> >content playing on pc
>
> Send to what? You can't just send it directly to the plama display.
> There has to be some kind of image assembler and disassembler.
>
> >which will be Flash files of different animations to the plasma,
anybody
> >ever done this?, and will it play smothly
>
> Well, that my trash my suggestion, but it's worth trying anyways.
If
> the PC running the flash animation is XP Pro, then run the "remote
> desktop" from a PC connected to the PC running the flash demo. If
> not, try using PC Anywhere or other remote desktop software. The
> problem is that it tends to be slow on refreshing the screen.
>
> There are also programs made for classroom instruction, where the
> instructors screen is reproduced on every machine in the classroom.
I
> think these run quite a bit faster.
>
> >But also the Hotel already has a Wireless network for the guests
laptops
> >Can we run two together?, We cant change the current AP so any
changes
> >have to be done to our setup
>
> Lovely. With the amount of traffic generated by a continuously
> running flash demo over wireless, unless you're on a different
> channel, you're gonna have an interference problem. If you need a
> computah to reconstruct the remote desktop, why not just stick
another
> computah on the plasma display and run the flash demo locally? Then
> you can syncronize the actions between the two PC's and not have to
> shovel over all the screen dump traffic.
>
> >Would it be better to run the plasma and pc in adhoc mode or as a
2nd AP?
>
> It doesn't really matter for this as the radio traffic is going to
be
> the same whether you use infrastructure mode, ad-hoc mode, or
> transparent bridging.
>
> >This will be playing 24hrs so I need to make sure these two
networks are not
> >going to crash each other,
>
> Oh swell, you also want it to be reliable? Sigh. The best way to
get
> problems solved is to explain:
> 1. what problem you are trying to solve
> 2. and what you have to work with.
> Methinks we have about half of each here. You're trying to display
> something continuously from a computah and you can't change
anything.
> I little more detail as to what you have to work with would be
> helpful.
>
> How about converting the video at the originating PC to video and
> shoving it down the hotels CATV system? Flash animations tend to be
> rather low resolution and should not require much bandwidth. You
> start with SVGA video, get a box that converts it to NTSC video or
> runs and RF modulator, feeds it to the CATV system, and recover the
> video with an ordinary plasma TV screen (using video). If they
don't
> want you to the CATV coax, get a TV wireless *VIDEO* extension
> transmitter and receiver (X10?) and use it instead of wireless data.
> However, be advised that you'll probably trash the hotels wireless
> network. Maybe a small UHF transmitter often used by the security
> camera people.
>
> If wireless turns into a mess, you can also share the CATV coax with
> ethernet. See:
> http://www.multilet.com/us/baseband/index.htm

They do make such a device, its a Wavecom Grandtec PC-2-TV wireless
converter.
1 box connects to the vga out on the PC and the other to the video in
on the TV.
It does operate in the 2.4 ISM band but has 4 channel selection
capability.
Works up to 50 metre. I cant bless it cause I havent tried it, but if
you do let us
know how it works!

Archived from groups: alt.internet.wireless (More info?)

"Peter Phillips" <pphillips@_SPAMTRAP_kinetiqnetworks.com> wrote in message
news:cpumcr$t0p$1@hercules.btinternet.com...
> Jeff Liebermann wrote:
> > On Thu, 16 Dec 2004 23:11:04 -0000, "Oliver Gunnell"
> > <Oliver.spamGunnell@dsl.pipex.com> wrote:
> >
> >
> >
> >>A hotel need a plasma display showing content from a pc but
> >>they don't wont us to run cables from a pc which is the best way of
course,
> >
> Your choice is:
>
> 1. Put a PC next to the plasma, connected directly via RCA from the
> sound/video card on the PC. Update the content locally or via a network
> connection, wired or wireless, it makes not much difference.
> 2. Put a PC away from the plasma and connect it via runs of Triax/RCA.
> Update via ethernet/wifi/cd/directly.

<SNIP>

The adaptor he wants to use extends the vga signal over the wireless
network.
so all you have is the screen and a adaptor. the PC is remotely located out
of harms way.


Ian

Archived from groups: alt.internet.wireless (More info?)

In article <32juksF3n1ubkU1@individual.net>,
Oliver Gunnell <Oliver.spamGunnell@dsl.pipex.com> wrote:

:If it was up to me we would just run a cat5 cable with vga tx/rx on each
:end but the hotel will not have any visable cables and we cant hide them
:as it's on a solid brick wall in the lobby.

There just happens to be some plants growing right by the plasma
screen ;-)
--
So you found your solution
What will be your last contribution?
-- Supertramp (Fool's Overture)

Archived from groups: alt.internet.wireless (More info?)

On Sun, 19 Dec 2004 00:00:28 -0000, "Oliver Gunnell"
<Oliver.spamGunnell@dsl.pipex.com> wrote:

>Exactly it's just a small box that becomes part of the network, I think it
>works using lynux and VNC or somthing like that and it has a VGA
>cable into the plasma, the unit is here www.madnat.co.uk under VGA

This one?
http://www.level1.com/products3.php?sklop=8&id=540515
No clue how they encode the video but my guess(tm) is that it doesn't
do any compression. With full motion uncompressed video screen dumps,
it could easily hog all the available wireless bandwidth.

>If it was up to me we would just run a cat5 cable with vga tx/rx on each
>end but the hotel will not have any visable cables and we cant hide them
>as it's on a solid brick wall in the lobby.

No existing telco wires or coax that you can borrow? You can possibly
run 10baseT over telco wires for short distances between switched
ports.

--
Jeff Liebermann jeffl@comix.santa-cruz.ca.us
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 AE6KS 831-336-2558